1. Field of the Invention
The instant disclosure relates to a film-covered LED device; more particularly, to a film-covered LED device for lighting.
2. Description of Related Art
In the current market, lighting devices such as fluorescent lamps, incandescent lamps, and recently adopted energy-saving bulbs are used commonly nowadays. However, most of these lamps have the disadvantages of rapid aging, high power consumption, high heat generation, short service life, break easily, being not recyclable, etc. Therefore, in response to above issues, the use of LED bulbs, lamps, and tubes have become available.
Please refer to FIGS. 1 and 2, wherein a conventional LED device 1a usually comprises a high thermal conductive substrate 10a, a reflector 11a, a plurality of LED chips 12a, and cured encapsulating gel 13a. A positive contact P and a negative contact N are paired at both ends of the high thermal conductive substrate 10a for power connection. A thru opening 111a is formed at the center of the reflector 11a, wherein the reflector 11a is disposed on the surface of the high thermal conductive substrate 10a. The LED chips 12a are disposed on the high thermal conductive substrate 10a and within the thru opening 111a. The cured encapsulating gel 13a includes fluorescent powders and fills the thru opening 111a, for mixing and distributing light beams.
Notably, the above LED device 1a is normally manufactured using the COB (Chip on Board) technology, which has the following disadvantages. First, when filling the thru opening 111a with the encapsulating gel 13a, a special apparatus must be used to accurately fill the hru opening 111a with the uncured encapsulating gel 13a, to maintain levelness. Next, the encapsulating gel 13a is baked for curing, which tends to have uneven thickness. Thereby, light distribution effectiveness is adversely affected.
Secondly, the encapsulating gel 13a has fluorescent powder, where the degree of concentration can be adjusted by the manufacturer as necessary, which affects the illumination efficiency of the LED chips 12a. Therefore, when replenishing the encapsulating gel 13a, the degree of concentration of fluorescent powder could not be certain is the same. The uniformity of illumination efficiency could not be maintained consequently, which affects the yield rate.
Thirdly, the steps of the COB technology are very involved. The manufacturing process requires considerable input of human resource, and the equipment cost is higher.
To address the above the issues, the inventor conducted related study and propose the following solution.